Journal: Journal of Huntington's Disease

Article Title: Morphological and functional phenotyping of skeletal muscle and bone in the zQ175 knock-in mouse model of Huntington's disease

doi: 10.1177/18796397251387208

Figure Lengend Snippet: Histomorphometric analysis of skeletal muscle reveals significant myofiber atrophy in 6-month-old homozygous zQ175 mice. (a) Schematic of the experimental workflow used for histological analysis of muscle cross-sections in the second cohort, which consisted of sex and age-matched 6-month-old mice (n = 5 per genotype), with each group comprising 3 males and 2 females. No sex-related differences were observed in body weight (data not shown) or in the subsequent CSA measurements. Illustration created with BioRender.com. (b) Representative image of a laminin-stained cross-section of extensor digitorum longus (EDL) muscle from a wild-type mouse, and corresponding myofiber region-of-interest (ROI) segmentation using Cellpose and LabelToROI plugins in Fiji. (c, e) Quantification of mean myofiber cross-sectional area (CSA) in EDL (c) and Soleus (e) muscles from 6-month-old homozygous zQ175 (HD) and wild-type (WT) mice (n = 5 per group, mixed sex). Bars represent the mean ± SD, where each point corresponds to the average CSA of all myofibers measured within a single muscle cross-section from one mouse (one section per mouse was analyzed, and this average value was used as a single data point for statistical analysis to ensure independence of observations). Statistical analysis was performed using unpaired two-tailed Student's t-test (**p < 0.01). (d, f) Frequency distribution histograms showing the percentage of myofibers falling within each CSA bin for EDL (d) and Soleus (f) muscles. Histograms were generated from the same muscle cross-sections used to generate the mean CSA values in panels (c) and (e), with the CSA of all individual myofibers in each section contributing to the bin distribution (n = 5 sections per group, one per mouse).

Article Snippet: The muscle contractility results were analyzed using Dynamic Muscle Data Analysis software (Aurora Scientific Inc.).

Techniques: Staining, Muscles, Two Tailed Test, Generated

Journal: Journal of Huntington's Disease

Article Title: Morphological and functional phenotyping of skeletal muscle and bone in the zQ175 knock-in mouse model of Huntington's disease

doi: 10.1177/18796397251387208

Figure Lengend Snippet: Contractile deficits in soleus muscles of 6-month-old homozygous zQ175 mice revealed by ex vivo functional analysis. Soleus muscles were dissected from the same 6-month-old male wild-type (WT) and homozygous zQ175 (HD) mice (cohort 1, n = 6 per group) and subjected to ex vivo physiological testing. (a–b) Soleus mass was recorded both relative to body weight, which did not differ significantly between groups, and as absolute dry mass, which was significantly reduced in HD mice compared to WT controls. (c) Force-frequency relationships showed significantly lower isometric force generation in HD muscles across stimulation frequencies from 35 to 150 Hz. (d–e) Peak twitch force (Pt) and maximal tetanic force (P 0 ) were both significantly reduced in HD mice. (f) Specific tetanic force (sP 0 ; force normalized to physiological cross-sectional area) was significantly decreased in HD mice. (g) Time to peak tension (TPT) was significantly prolonged in HD mice, whereas (h) half-relaxation time (1/2 RT) remained unchanged. Data are presented as mean ± SD. Statistical comparisons were performed using unpaired two-tailed Student's t-test. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001; ns: not significant.

Article Snippet: The muscle contractility results were analyzed using Dynamic Muscle Data Analysis software (Aurora Scientific Inc.).

Techniques: Muscles, Ex Vivo, Functional Assay, Two Tailed Test